Circuit tester



J. J. EAGAN CIRCUIT TESTER Feb. 29, 1944.

Filed April 17, 1943 a .m T

IN V EN TOR.

MW WM J W 9 Ml Wzinesses Patented Feb. 29, 1944 UNITED STATES PATENT OFFICE CIRCUIT TESTER,

John J. Eagan, Yonkers, N. Y.

Application April 17, 1943, Serial No. 483,388

6 Claims.

This invention relates to a testing device and more particularly to a device to test electrical systems such as ignition, spark plugs, etc.

An object of this invention is to provide a simple, inexpensive device by which the systems being tested may be visually checked. Another object is to provide a device which may be used at a convenient distance from the place being checked and which may be placed upon metal parts without damage of short circuit. This is a particular advantage in checking ignition systems in modern cars where the hood construction makes access to the motor difficult.

A further object is to provide an article of the type described which will be extremely simple in construction and operation and which may be easily operated with one hand. Another object is to provide a device of the character described which will conserve strategic materials and which may be sold at a relatively low price.

Referring to the accompanying drawing,

Figure 1 is a side elevation partly in cross sec tion of an embodiment of my device.

Figure 2 is a top View of the same device.

Figure 3 is a cross sectional view taken on the line 33 of Figure 4.

Figure 4 is a modified form of my device.

Figure 5 is a cross sectional view taken on .the line 55 of Figure 4.

My device consists essentially of three elements, two insulating wires and an insulated handle terminating in an opening visible to the operator. The handle member I!) may be made of wood or other non-conducting material and may be shaped to conveniently fit the hand. The handle member is bored through at I l and I2 to form two longitudinal bores. It is cut away at M and 15. The wire it is fixed in the bore I2 by means of a pin I! with one end IS in the opening [4. Another wire extends through the bore II and is doubled upon itself through the bore l2. The wire need not be fixed and is slidable within the bore l2 having its end 2| entering the opening M and a portion 22 exposed in the cutaway l5. It will be seen that the device may be held in one hand and the distance between the ends of the wire varied by a simple movement of the thumb. It will be understood that the wires 16 and 20 are insulated and that they may be provided with conventional clamps at their outer ends for contact with the unit to be tested. Graduations 25 may be provided along the cutout portion M to indicate the size of the spark.

In the form shown in Figures 4 and 5, the handle member 39 may be made of transparent plastic 1 in which event it is not necessary to cut away portions to show the spark gap since it may readily be seen through the transparent plastic. If desired, however, a magnifying glass 3| may be mounted over the opening 32 so that the spark may be more readily seen. It will be appreciated that the shape of my handle member may be varied considerably and that the wire 26 may be fixed in the bore l I if desired although this is not necessary.

I claim:

1. A testing device including a handle memher, a pair of bores through said handle member, said handle member being cut away to expose one of said bores in two places, an insulated wire fixed in said cutaway bore with an end adjacent to one of said openings graduations adjacent said openings and a second insulated wire extending through both bores, said second wire having an end adjacent said first mentioned wire and a portion of said wire being exposed by said second cut away portion whereby said second wire may be moved within said bore.

2. A testing device including a handle member, a pair of bores through said handle member, insulated wire fixed in one of said bores, said handle member being cut away to form an opening to expose the end of said wire, a second wire extending through the other of said bores and returned upon itself into the first mentioned bore, said wire having its end adjacent said opening a series of graduations adjacent said opening and said handle member being cut away to expose an insulated portion of said second wire whereby said second wire may be moved within said bore.

3. A testing device including a handle member, a bore in said handle member, a wire extending into said bore, said wire being fixed, and a second wire extending into opposite end of said bore being movable therein, said handle member being cut away to expose a portion of said bore and said second wire and a series of gage lines adjacent the end of the said fixed wire to indicate the distance between said fixed wire and said movable wire.

4. A testing device including a handle member having a bore therethrough, portion of said handle being cut away to form an opening to said bore, a wire fixed in said bore with its end adjacent said opening a series of gage lines on said handle member adjacent said opening, a second wire in the opposite end of said bore having its end in said opening and a second opening in said handle member whereby said second wire may be moved in and out of said opening.

fixed in said bore a series of gage lines adjacent the end of said fixed wire, a second wire slidable in said here, an opening in said handle member exposing said bore and said second wire whereby 5 said second wire may be moved toward or away from first said mentioned wire.

JOHN, J. EAGAN. 

